Functional connectivity of reflective and brooding rumination in depressed and healthy women

Ruminative thinking is related to an increased risk for major depressive disorder (MDD) and perpetuates negative mood states. Rumination, uncontrollable negative thoughts about the self, may comprise both reflective and brooding components. However, only brooding rumination is consistently associated with increased negativity bias and negative coping styles, while reflective rumination has a less clear relationship with negative outcomes in healthy and depressed participants. The current study examined seed-to-voxel (S2.V) resting-state functional connectivity (FC) in a sample of healthy (HC) and depressed (MDD) adult women (HC: n=50, MDD: n=33). The S2V FC of six key brain regions, including the left and right amygdala, anterior and posterior cingulate cortex (ACC, PCC), and medial and dorsolateral prefrontal cortices (mPFC, dlPFC), was correlated with self-reported reflective and brooding rumination. Results indicate that HC and MDD participants had increased brooding rumination associated with decreased FC between the left amygdala and the right temporal pole. Moreover, reflective rumination was associated with distinct FC of the mPFC, PCC, and ACC with parietal, occipital, and cingulate regions. Depressed participants, compared with HC, exhibited decreased FC between the PCC and a region in the right middle frontal gyrus. The results of the current study add to the understanding of the neural underpinnings of different forms of self-related cognition—brooding and reflective rumination—in healthy and depressed women.     

Prediction and unconscious attention operate synergistically to facilitate stimulus processing: An fMRI study

There is considerable evidence that prediction and attention aid perception. However, little is known about the possible neural mechanisms underlying the impact of prediction and unconscious attention on perception, probably due to the relative neglect of unconscious attention in scholarly literature. Here, we addressed this issue using functional magnetic resonance imaging (fMRI). We adopted a variant of the double-cue paradigm, in which prediction and attention were factorially manipulated by two separate cues (prediction and attention cues). To manipulate consciousness, the attention cues were presented subliminally and supraliminally. Behaviorally, we reported an unconscious-attended effect in the predictable trials and a conscious-attended effect in the unpredictable trials. On the neural level, it was shown that prediction and unconscious attention interacted in the left dorsolateral prefrontal cortex (dlPFC). More specifically, there was a significantly decreased activation in dlPFC for predictable relative to unpredictable stimuli in the unconscious-attended trials, but not in the unconscious-unattended trials. This result suggests that prediction and unconscious attention operate synergistically to facilitate stimulus processing. This is further corroborated by the subsequent functional connectivity analysis, which revealed increased functional connectivity between the left dlPFC and the premotor cortex for predictable versus unpredictable stimuli in the unconscious-attended trials.     

长期戒断海洛因成瘾者冲动性相关脑区的结构及功能特征

冲动性是药物成瘾者的典型特征, 它既包含了抑制控制成瘾者药物使用的力量, 也包含驱动成瘾者使用药物的成分, 两者不平衡导致冲动性用药行为。海洛因成瘾者本身具有冲动性人格特质, 长时间的海洛因使用又会造成成瘾者冲动性相关的大脑结构与功能的异常。目前难以确定戒断后, 冲动性及相关的大脑结构与功能是否还呈异常状态。本研究采用基于体素的形态学分析、低频振幅、局部一致性和功能连接方法, 以35例海洛因成瘾戒断者和无任何成瘾史的健康个体26人为研究对象, 探索在长期戒断后, 海洛因成瘾者与其冲动性相关的驱动、控制系统脑网络的结构和功能情况。结果显示, 相比对照组, 戒断组灰质总体积及右内侧额上回的灰质体积显著减小, 右侧颞中回和左内侧旁扣带回的灰质体积随用药总量的增加而降低; 右侧眶部额下回与尾状核功能连接显著增强, 右侧颞中回和左侧中央前回功能连接显著降低; 右眶额中回的ReHo值、右眶额下回和左海马体的ALFF值比对照组显著更低, 而右中央后回的ReHo值显著更高。这些脑区的状况与冲动性的神经基础相吻合, 说明海洛因成瘾戒断者在戒断44个月, 奖赏、凸显、习惯性行为等网络系统仍然呈现异常状态, 且与成瘾药物使用总量有关。这些异常可能是成瘾冲动性的驱动力的神经基础, 可以作为解释成瘾者戒断后容易复吸的因素之一。     

The association between the propensity to experience meaningful coincidence and brain anatomy in healthy females: The moderating role of coping skills

When two events co-occur within a specific time interval, some people experience ‘meaningful coincidence’. This may be a consequence of the mind searching for causal structure in reality. In cases of negative events, it may be a coping strategy for managing stress. The present voxel-based morphometry (VBM) study investigated neural correlates of the propensity to experience meaningful coincidence (PEMC). VBM data from 115 females (mean age: 26 years) were correlated with self-reported PEMC and the use of certain coping strategies (e.g. seeking support, positive focusing). PEMC was negatively correlated with grey matter volume (GMV) in the medial prefrontal cortex, the inferior frontal gyrus, and the superior/inferior parietal cortex. Moderation analyses indicated that the negative association between GMV in the mentioned brain regions and PEMC was only present in participants with average or below-average coping skills. The identified fronto-parietal regions are part of an integrated neural network implicated in the detection of causality and cognitive control.     

拖延的认知神经机制与基因:行为-脑-基因的多角度研究

拖延是一种普遍存在,具有跨时间和跨情景稳定性的问题行为,严重的拖延甚至会危害到人们的工作、学习及身心健康。鉴于目前对于拖延的认知神经机制仍不清楚,研究模态较为单一,本研究拟从行为-脑-基因的系统研究思路出发,以多模态MRI(Task、Resting、VBM和DTI)为主要技术手段,将HTR2B基因多态性作为突破口,系统考察拖延的认知机制、神经基础和遗传基础,并试图制定拖延的应对与干预方案。研究分为4个部分:(1)从行为上,结合预期恐惧范式和跨期选择范式探索其拖延决策的机制;(2)在神经层面上,采用MRI多模态技术系统考察拖延行为的神经基础;(3)在基因层面上,采用分子遗传学方法,将HTR2B设定为靶基因以深入研究拖延的遗传基础,并考察脑结构和脑功能在基因与行为间的中介作用;(4)最后从行为干预与脑的可塑性的角度,设计拖延的干预方法来改善拖延行为并验证拖延的神经机制。     

藏汉双语者汉语阅读理解的静息态功能连接分析

研究结合静息态全脑功能连接密度和基于种子点的功能连接（FC）分析考察了藏汉双语者汉语（L2）阅读各子能力（细节捕捉和推理判断）的固有脑功能组织特点。结果发现左侧额下回—左侧颞上回和右侧舌回—右侧中央前回之间的FC值均与细节捕捉题得分和推理判断题得分呈显著正相关,但是左侧额下回—右侧顶下小叶之间的FC值只与推理判断题得分呈显著正相关。表明藏汉双语者汉语阅读各子能力之间既有重叠的又有不同的功能连接通路。     

拖延行为的认知神经模型及干预

拖延是一种普遍存在, 具有跨时间和跨情景稳定性的问题行为, 它会危害到人们的学习、工作和身心健康。然而目前拖延行为的认知神经机制仍不清晰, 且缺乏因果证据, 本项目拟从拖延的时间决策模型和三重神经结构网络模型出发, 构建拖延的认知神经模型, 并利用认知干预和神经调控技术, 检验和完善拖延行为的认知神经模型, 进而试图制定拖延的精准化干预方案。本项目分为3部分：(1)从记录与关联研究的视角出发, 利用多模态神经影像方法系统考察拖延行为的认知神经机制; (2)从因果/近因果研究视角出发, 利用认知干预和神经调控技术, 验证并完善拖延的认知神经模型; (3)从临床应用的视角出发, 建立拖延行为障碍的临床筛查-诊断体系, 并制定精准化治疗方案。本项目的开展对于探明拖延产生的核心认知神经机制具有十分重要的理论贡献, 同时对于拖延行为的有效预防和精准治疗具有重要的现实意义。     

重复经颅磁刺激对轻度认知障碍的干预效果

轻度认知障碍(mild cognitive impairment, MCI)是介于正常认知老化和老年痴呆的中间状态, 目前尚无有效的药物治疗方案。重复经颅磁刺激(repetitive transcranial magnetic stimulation, rTMS)可通过诱导突触可塑性的改变来改善大脑的认知功能。对rTMS干预MCI认知功能的有效性及神经机制进行分析。未来研究应优化定位手段, 延长对干预效果的随访评估, 考察不同刺激参数和刺激靶区对干预有效性的影响, 以及结合脑成像技术来探索rTMS的干预机制。     

网络教学情境下正念对学业拖延的影响：心理韧性和自我控制的链式中介作用

本研究以157名大学生为对象,选用正念五因素量表、心理韧性量表、自我控制量表和Aitken拖延量表,探索在网络教学情境下正念对学业拖延的作用机制。结果表明：正念能够直接对网络教学情境下的大学生学业拖延产生影响,也能够通过心理韧性和自我控制的链式中介作用对大学生学业拖延产生影响。研究结论为发挥正念的作用,改善网络教学情境下的学业拖延提供了参考。     

自我控制对睡眠质量的影响:反刍思维与就寝拖延的中介作用

本研究主要考察了自我控制对睡眠质量的影响作用,以及反刍思维和就寝拖延的中介作用。采用相关量表对1104名大学生进行问卷调查。研究结果表明:(1)自我控制可以负向预测睡眠质量问题、反刍思维和就寝拖延。(2)自我控制还通过反刍思维和就寝拖延的单独中介及序列中介,间接影响睡眠质量。     

Effects of transcranial direct current stimulation on neural activity and functional connectivity during fear extinction

Background/ObjectiveAnxiety disorders are highly prevalent and negatively impact daily functioning and quality of life. Transcranial direct current stimulation (tDCS) targeting the dorsolateral prefrontal cortex (dlPFC), especially in the right hemisphere impacts extinction learning; however, the underlying neural mechanisms are elusive. Therefore, we aimed to investigate the effects of cathodal tDCS stimulation to the right dlPFC on neural activity and connectivity patterns during delayed fear extinction in healthy participants.MethodsWe conducted a two-day fear conditioning and extinction procedure. On the first day, we collected fear-related self-reports, clinical questionnaires, and skin conductance responses during fear acquisition. On the second day, participants in the tDCS group (n = 16) received 20-min offline tDCS before fMRI and then completed the fear extinction session during fMRI. Participants in the control group (n = 18) skipped tDCS and directly underwent fMRI to complete the fear extinction procedure. Whole-brain searchlight classification and resting-state functional connectivity analyses were performed.ResultsWhole-brain searchlight classification during fear extinction showed higher classification accuracy of threat and safe cues in the left anterior dorsal and ventral insulae and hippocampus in the tDCS group than in the control group. Functional connectivity derived from the insula with the dlPFC, ventromedial prefrontal cortex, and inferior parietal lobule was increased after tDCS.ConclusiontDCS over the right dlPFC may function as a primer for information exchange among distally connected areas, thereby increasing stimulus discrimination. The current study did not include a sham group, and one participant of the control group was not randomized. Therefore, to address potential allocation bias, findings should be confirmed in the future with a fully randomized and sham controlled study.     

Functional connectivity in an fMRI study of semantic and phonological processes and the effect of L-Dopa

We describe an fMRI experiment examining the functional connectivity (FC) between regions of the brain associated with semantic and phonological processing. We wished to explore whether L-Dopa administration affects the interaction between language network components in semantic and phonological categorization tasks, as revealed by FC. We hypothesized that L-Dopa would decrease FC due to restriction of the semantic network. During two test sessions (placebo and L-Dopa) each participant performed two fMRI runs, involving phonological and semantic processing. A number of brain regions commonly activated by the two tasks were chosen as regions if interest: left inferior frontal, left posterior temporal and left fusiform gyri, and left parietal cortex. FC was calculated and further analyzed for effects of either the drug or task. No main effect for drug was found. A significant main effect for task was found, with a greater average correlation for the phonological task than for the semantic task. These findings suggest that language areas are activated in a more synchronous manner for phonological than for semantic tasks. This may relate to the fact that phonological processes are mediated to a greater extent within language areas, whereas semantic tasks likely require greater interaction outside of the language areas. Alternatively, this may be due to differences in the attentional requirements of the two tasks.     

预先承诺的理论解释及其神经机制

预先承诺是指个体提前做出一个有长远目标的决定来限制对即时诱惑的选择,从而避免在未来决策中由于意志力缺乏而出现的自我控制失败。最后期限法和限制选择法是开展预先承诺研究的常用范式。本研究在系统回顾预先承诺的三种理论解释（自我控制资源模型、神经网络模型和时间差强化学习模型）的基础上,尝试提出一个整合性的认知神经机制模型来解释预先承诺的作用过程。未来研究可进一步丰富预先承诺的研究范式和应用范围,并探究预先承诺调控非理性决策的心理与神经机制。     

预先承诺的理论解释及其神经机制

预先承诺是指个体提前做出一个有长远目标的决定来限制对即时诱惑的选择,从而避免在未来决策中由于意志力缺乏而出现的自我控制失败。最后期限法和限制选择法是开展预先承诺研究的常用范式。本研究在系统回顾预先承诺的三种理论解释（自我控制资源模型、神经网络模型和时间差强化学习模型）的基础上,尝试提出一个整合性的认知神经机制模型来解释预先承诺的作用过程。未来研究可进一步丰富预先承诺的研究范式和应用范围,并探究预先承诺调控非理性决策的心理与神经机制。     

The influence of maternal anxiety and depression symptoms on fNIRS brain responses to emotional faces in 5- and 7-month-old infants

Greater relative right (versus left) frontal cortical activation to emotional faces as measured with alpha power in the electroencephalogram (EEG), has been considered a promising neural marker of increased vulnerability to psychopathology and emotional disorders. We set out to explore multichannel fNIRS as a tool to investigate infants’ frontal asymmetry responses (hypothesizing greater right versus left frontal cortex activation) to emotional faces as influenced by maternal anxiety and depression symptoms during the postnatal period. We also explored activation differences in fronto-temporal regions associated with facial emotion processing. Ninety-one typically developing 5- and 7-month-old infants were shown photographs of women portraying happy, fearful and angry expressions. Hemodynamic brain responses were analyzed over two frontopolar and seven bilateral cortical regions subdivided into frontal, temporal and parietal areas, defined by age-appropriate MRI templates. Infants of mothers reporting higher negative affect had greater oxyhemoglobin (oxyHb) activation across all emotions over the left inferior frontal gyrus, a region implicated in emotional communication. Follow-up analyses indicated that associations were driven by maternal depression, but not anxiety symptoms. Overall, we found no support for greater right versus left frontal cortex activation in association with maternal negative affect. Findings point to the potential utility of fNIRS as a method for identifying altered neural substrates associated with exposure to maternal depression in infancy.     

Structural brain abnormalities in patients with Parkinson’s disease with visual hallucinations: A comparative voxel-based analysis

The objective is to evaluate clinical characteristics and cerebral alterations in Parkinson’s disease (PD) patients with diurnal visual hallucinations (VHs). Assessment was performed using magnetic resonance image (MRI) and voxel-based morphometry (VBM). Thirty-nine patients with PD (53.8%) and ten controls were studied. Voxel based morphology analysis was performed. Eleven patients presented diurnal VHs and among these, six had cognitive dysfunction. Patients with VHs performed worse in the mentation-related UPDRS I (p = 0.005) and motor-related UPDRS III (p = 0.02). Patients with VHs showed significant clusters of reduced grey matter volume compared to controls in the left opercula frontal gyrus and left superior frontal gyrus. PD without hallucinations demonstrated reduced grey matter volume in the left superior frontal gyrus compared to controls. Comparisons between patients with VHs regarding the presence of cognitive dysfunction showed that cases with cognitive dysfunction as compared to those without cognitive dysfunction showed significant clusters of reduced grey matter volume in the left opercular frontal gyrus. Cases without cognitive dysfunction had reduced grey matter substance in the left insula and left trigonal frontal gyrus. Judging from our findings, an abnormal frontal cortex, particularly left sided insula, frontal opercular, trigonal frontal gyrus and orbital frontal would make PD patients vulnerable to hallucinations. Compromise of the left operculum distinguished cases with VHs and cognitive dysfunction. Our findings reinforce the theoretical concept of a top-down visual processing in the genesis of VHs in PD.     

In the trenches of real-world self-control: neural correlates of breaking the link between craving and smoking

Successful goal pursuit involves repeatedly engaging self-control against temptations or distractions that arise along the way. Laboratory studies have identified the brain systems recruited during isolated instances of self-control, and ecological studies have linked self-control capacity to goal outcomes. However, no study has identified the neural systems of everyday self-control during long-term goal pursuit. The present study integrated neuroimaging and experience-sampling methods to investigate the brain systems of successful self-control among smokers attempting to quit. A sample of 27 cigarette smokers completed a go/no-go task during functional magnetic resonance imaging before they attempted to quit smoking and then reported everyday self-control using experience sampling eight times daily for 3 weeks while they attempted to quit. Increased activation in right inferior frontal gyrus, pre-supplementary motor area, and basal ganglia regions of interest during response inhibition at baseline was associated with an attenuated association between cravings and subsequent smoking. These findings support the ecological validity of neurocognitive tasks as indices of everyday response inhibition.     

顿悟的大脑机制

自从柯勒1917年提出顿悟的概念以来,这个问题一直吸引着心理学家的关注。但有关顿悟过程的精确的大脑机制却始终未被触及。从心理过程上看,顿悟是一个瞬间实现的、问题解决视角的“新旧交替”过程;它包含两个方面,一是新的有效的问题解决思路如何实现,二是旧的无效的思路如何被抛弃（即打破思维定势）。我们以谜语作为材料,利用功能性磁共振成像（fMRI）技术精确记录了人类的大脑在实现顿悟的一瞬间的活动状况。结果显示顿悟过程激活了包括额叶、颞叶、扣带前回、以及海马在内的广泛脑区。根据各方面的综合证据,本文认为：顿悟过程中,新异而有效的联系的形成依赖于海马,问题表征方式的有效转换依赖于一个“非语言的” 视觉空间信息加工网络,而思维定势的打破与转移则依赖于扣带前回与左腹侧额叶。     

Implicit threat learning involves the dorsolateral prefrontal cortex and the cerebellum

Background/ObjectiveMost studies investigating the neural correlates of threat learning were carried out using an explicit Pavlovian conditioning paradigm where declarative knowledge on contingencies between conditioned (CS) and unconditioned stimuli (US) is acquired. The current study aimed at understanding the neural correlates of threat conditioning when contingency awareness is limited or even absent.MethodWe conducted an fMRI report of threat learning in an implicit associative learning paradigm called multi-CS conditioning, in which a number of faces were associated with aversive screams (US) such that participants could not report contingencies between the faces and the screams.ResultsThe univariate results showed support for the recruitment of threat-related regions including the dorsolateral prefrontal cortex (dlPFC) and the cerebellum during acquisition. Further analyses by the multivariate representational similarity technique identified learning-dependent changes in the bilateral dlPFC.ConclusionOur findings support the involvement of the dlPFC and the cerebellum in threat conditioning that occurs with highly limited or even absent contingency awareness.     

Brief mindfulness meditation intervention improves attentional control of athletes in virtual reality shooting competition: Evidence from fNIRS and eye tracking

Attentional control is a crucial cognitive ability for sports performance. The current research aimed to investigate whether a brief (20-min) pre-competition mindfulness meditation (MM) intervention enhances athletes' attentional control during competitions and alters the activity of brain regions related to attentional control. We created a virtual reality shooting competition to compare the eye-gaze indicators and functional near-infrared spectroscopy (fNIRS) parameters of 78 university athletes after 20 min of MM or 20 min of mind wandering (MW). Participants’ average fixation durations (AFDs) on task-relevant information (targets) were significantly longer in the MM group. In contrast, both average fixation counts (AFCs) and AFDs on task-irrelevant information (the ranking screen) were significantly lower in the MM group than in the MW group. Additionally, the MM group exhibited significantly stronger activation of the left and right dorsolateral prefrontal cortex (dlPFC) as well as higher levels of oxygenated haemoglobin [HbO] and greater functional connectivity (FC) of the right dlPFC, which was considered evidence of recruitment for attentional control. Moreover, the MM group achieved significantly better shooting performance than the MW group. Overall, the findings suggest that one session 20-min MM practice pre-competition facilitates focus during competition and improves athletic performance. We recommend the application of brief mindfulness practice in sports, especially in closed-skill sports that require high attention participation (e.g., shooting, archery, darts, golf, gymnastics, skating etc.).